Gross Reservoir was completed in 1954 and named for Denver Water former Chief Engineer Dwight D. Gross. It was built for water storage for municipalities in the Greater Denver area.  The utility company Denver Water diverts a significant portion of the headwaters of the Colorado River, west of the Continental Divide, through the Moffat Tunnel to be stored in Gross Reservoir over 20 miles away, east of the Divide.  During the summer months, when municipal water usage is significantly higher due to landscaping (over 50% of Denver Water’s total water consumption goes to this purpose), Gross Reservoir feeds into Denver Water’s supply system, contributing roughly 5% of the overall quota.  During the fall, winter and spring seasons, Gross Reservoir is shut down for recharging.Gross Reservoir is a Denver Water storage site.

Today Colorado residents and tourists alike enjoy its beauty, waterfalls, fishing, hiking and biking trails. Denver Water is proposing a massive expansion of Gross Dam and Reservoir that would have huge negative impacts on many citizens in Boulder County and on Boulder Country’s environment. Despite what Denver Water’s propaganda states, this project is NOT a done deal. Please review the bullet points and videos here that have been put together by concerned citizens over the years to educate yourself on the problems with this huge construction project. And then consider getting active – we need your help to stop this travesty!

 

Denver Water is proposing to increase the height of Gross Dam from 340 feet to 465 feet, nearly tripling the reservoir’s storage capacity from 41,811 to 114,000 acre-feet.  The utility claims that the $140M+ expansion, dubbed the Moffat Collection System Project, would help resolve three major water supply challenges: the risk of a near-term water supply shortfall; the risk of running out of water in the north end of Denver Water’s system during a single dry year; and a serious imbalance in Denver Water’s water collection system.

Issues with this proposal include

  • Denver Water asserts that total water supply will equal demand in 2022. No numeric data are given to support this. The purpose and need for the Moffat Project is based on projections of water supply and demand cannot be validated. Per Denver Water’s own 2015 Comprehensive Annual Financial Report, treated water consumption is decreasing as population is increasing.
  • Denver Water assets that Gross Reservoir must be expanded to address an imbalance between the north / south system. The entire supply system is immense, has built in flexibility and is reliable as has been demonstrated during the drought of 2002-2004. Reservoir capacity does not tell the entire story. The critical pinch point is the capacity of the Moffat Treatment Plant. Additional storage in Gross Reservoir does not change that capacity.
  • The problem to be solved is not lack of stored water – it is lack of a conveyance system. The solution to getting water north is not by compensating with a bigger reservoir, but by building conveyance systems that bring raw water directly to Moffat Treatment Plant.
  • Tree removal: Destruction of over 200,000 trees is obviously environmentally damaging and the method of cutting and disposal of the trees is not clear.  If burned on site, the air pollution will be significant.  If hauled out, the steepness of the terrain and the lack of accessibility to the areas is only via steep, curvy dirt roads so safety is a prime concern.
  • Quarry: Destruction of land for the in-site quarry cannot be mitigated.  The sound and dust pollution from operation of the quarry will have significant impacts on residents, visitors and wildlife alike.
  • Loss of habitat: 465 acres of inundated land affect the human residents and will eradicate critical habitat for the deer, elk, moose, coyote, bobcat, mountain lion and innumerable bird species that inhabit the area.
  • Road safety: Impacts to residential traffic along Highway 72 will be significant.  Denver Water has not addressed the traffic hazards in any meaningful manner.  Even if one ignores the impact of up to 50 truck trips a day in terms of noise and slowing of traffic, the hazards to drivers, pedestrians, motorcyclists and bicyclists is extreme.
  • Lack of water: There is simply not enough water available from involved Western Slope drainages to fill an expanded reservoir most years. Residents and recreationalists will see a barren shoreline with the reservoir less than half full at least half the time. The effects of climate change on the water supply available from the Western Slopes is not even considered. Acres of wetlands on the Western Slope will suffer, streams will run dry and ultimately the Colorado River, already the most endangered river in the United States, will be effected.
  • Recreation: Visitor numbers to Gross Reservoir are significant. The disruption of recreation activities due to construction, years of blasting, tree removal, and traffic interruptions will be huge.  The loss of scenic areas, the drowning of Forsythe Falls, and closures to boating, fishing, hiking, picnicking and other visitor activities have not been addressed.
  • Seismology: Earthquake potential due to increased pressure caused by a larger reservoir has not be analyzed.

 

What Can I Do?

Use the button below to Subscribe to the TEG newsletter. We will notify you when we need letters written, community attendance at government meetings, etc.  And please consider donating to our legal fund – stopping this will require litigation and that costs money! Donate now using the button on the top right of this page.

More on what you can do.

Thank you!

If you would love to help with our initiative to stop the expansion of Gross Reservoir, please consider donating using the green button at the upper right of this page.